title: Substitutional disorder and charge localization in manganites.
abstract: In the manganites RE(1 - x)AE(x)MnO(3) (RE and AE being rare-earth and alkaline-earth elements, respectively) the random distribution of RE(3 + ) and AE(2 + ) induces random, but correlated, shifts of site energies of charge carriers in the Mn sites. We consider a realistic model of this diagonal disorder, in addition to the double-exchange hopping disorder, and investigate the metal-insulator transition as a function of temperature, across the paramagnetic-ferromagnetic line, and as a function of doping  x. Contrary to previous results, we find that values of parameters, estimated from the electronic structure of the manganites, are not incompatible with the possibility of a disorder-induced metal to insulator transition accompanying the ferromagnetic to paramagnetic transition at intermediate doping (x ∼ 0.2-0.4). These findings indicate clearly that substitutional disorder has to be considered as an important effect when addressing the colossal magnetoresistance properties of manganites.
authors.affiliation: CFP and Departamento de Física, Faculdade de Ciências Universidade do Porto, P-4169-007 Porto, Portugal. evcastro@fc.up.pt
authors.forename: Eduardo V
authors.initials: EV
authors.lastname: Castro
authors.forename: J M B Lopes
authors.initials: JM
authors.lastname: Dos Santos
mesh_terms: D017895:Manganese Compounds / Q000737:chemistry*; D008673:Metals, Alkaline Earth / Q000737:chemistry*; D008674:Metals, Rare Earth / Q000737:chemistry*; D008962:Models, Theoretical
chemical_list: D017895:Manganese Compounds; D008673:Metals, Alkaline Earth; D008674:Metals, Rare Earth; C494384:manganite